1. Field of the Invention
This invention relates to high-temperature-service bag filters having improved filtration performance.
2. Description of Related Art
Filter felts and bag filters for hot gas filtration containing aramid staple fibers, such as disclosed in U.S. Pat. Nos. 4,100,323 and 4,117,578 to Forsten can be used to protect the environment from particulate matter from asphalt plants, coal plants, and other industrial concerns. Due to the high potential environmental impact from such plants and the extreme chemical environment the filters must endure, any improvement that has the potential to improve filtration efficiency is desired.
In particular, the trend in the industry is for more portable asphalt manufacturing facilities and associated bag houses that can be operated where paving of roads is needed. These portable bag houses are generally more compact and use smaller bags on the order of about 3.5 meters in length, versus older larger bags of about 6 meters in length. Therefore there is a need for a filter bag that can provide improved performance at lower filter bag weight.